The present invention relates to electroless plating processes also known as chemical or autocatalytic plating. In particular this invention relates to compositions and methods of treating non-conductors to make them receptive to metallic deposition thereon.
Methods for the catalytic treatment of non-conductive (dielectrics) substrates to make them receptive to chemical plating are well known in the art as described in patents and technical publication. The following patents and articles are a few fully describing the state of the art and they are included within this application by reference U.S. Pat. Nos.
3,011,920; 3,672,923; 3,672,938; 2,421,079; PA1 3,532,518; 3,961,109; 3,841,881; 3,904,792; PA1 3,874,882; 2,303,871; 2,702,253; 3,093,509; PA1 3,379,556; 3,425,946; 3,607,352; 3,616,296; PA1 3,627,558; 3,664,860; 3,666,527; 3,674,550; PA1 3,682,671; 3,698,919; 3,767,583; 3,871,889; PA1 3,874,897; 3,902,908; 3,790,400. PA1 1. N. Feldstein et al, J. Electrochem. Soc., 119, 1486 (1972) and references therein are included. PA1 2. R. L. Meek et al, proceeding of "Fifth Plating in the Electronics Industry Symposium," N.Y., Mar. 24, 1975. PA1 3. G. A. Krulik, "The Catalytic Process in Electroless Plating," presented at the Am. Electroplaters Society, Denver, June 30, 1976. PA1 1. In all prior art the main emphasis was focussed upon combinations of tin(II) and palladium(II) used sequentially or in combination. PA1 2. In all cases acid(s) have been used as an integral part of the composition. PA1 3. In those cases in which tin(IV) was incorporated its concentration was significantly lower in comparison to the tin(II) concentration. In fact, many skilled in the art have tried to avoid its presence. PA1 4. A wide variety of anti-oxidant have been incorporated as to minimize the air oxidation of the tin(II). PA1 5. the so called "one step catalyst" after Shipley U.S. Pat. No. 3,011,920 and related patents were generally found ineffective when used on vitreous (glass, ceramic, oxides and the like) matter. It is noted that there are commercially available plastics which behave in a similar fashion to the vitreous matter.
Technical articles:
Also, Pending Applications Ser. Nos. 607,506 now U.S. Pat. No. 3,993,799 and 521,901 now U.S. Pat. No. 3,993,491 by the present applicant.
Summarizing the prior art (patents and publications) reveals: